Assembly

INSTALL OR CONNECT





Tools Required:
J 29710 Differential Side Bearing Installer
J 7818 Rear Pinion Bearing Cup Installer
J 7817 Front Pinion Bearing Cup Installer
J 8092 Driver Handle
- Pinion bearing cups using J 29710, J 7818, and J 8092 or equivalents.

Pinion Depth Adjustment
Tools Required:
J 21777-40 Rear Pilot Washer
J 21777-42 Front Pilot Washer
J 21777-43 Stud Assembly Bolt
J 21777-45 side Bearing Discs
J 23597-1 Arbor
J 23597-11 Gauge Plate
J 8001 Dial indicator

1. Clean all the gauge parts.








2. Lubricate the front and rear pinion bearings with axle lubricant.
3. Place the bearings into the pinion bearing cups.





4. Install J 21777-40, J 21777-42, J 21777-43, and J 23597-11 or equivalents, to the pinion bore.
5. Hold the stud stationary at the flats of the stud.
- Tighten
Stud nut to 2.2 Nm (20 inch lbs.).
6. Rotate the gauge plate and bearings several complete revolutions to seat the bearings.
7. Tighten the stud nut until a torque of 1.6 to 2.2 Nm (15 to 25 inch lbs.) is obtained to keep the gauge plate in rotation.





8. Assemble J 21777-45, J 23597-11, and J 8001 or equivalents, to the differential bearing bores as shown.
- The bearing bores must be clean and burr free.
9. Install the side bearing caps and tighten the bolts.
- Tighten
Bolts to 75 Nm (55 ft. lbs.).
10. Rotate the gauge plate until the gauging areas are parallel with the discs.
11. Position the gauge shaft assembly in the carrier so that the dial indicator rod is centered on the gauge area of the gauge block.
12. Set the dial indicator at zero. Push the indicator down on the indicator shaft until the needle rotates approximately 3/4 of a turn clockwise. Tighten the dial indicator in this position.
13. Rotate the gauge shaft slowly back and forth until the dial indicator reads the greatest deflection. This is when the indicator needle is centered between moving to the left and to the right.
14. At the point of greatest deflection, set the dial indicator to zero. Repeat the rocking action of the gauge shaft to verify the zero setting.
15. Rotate the gauge shaft until the dial indicator rod does not touch the gauge block.
16. Record the actual number on the dial indicator and not the number that represents how far the needle travels. This is the nominal pinion setting.





EXAMPLE: If the indicator needle moved counterclockwise 1.70 mm (0.067 inch) to a dial reading of 0.84 mm (0.033 inch) as shown, record the dial reading of 0.84 mm (0.033 inch) NOT 1.70 mm (0.067 inch). The dial indicator should be in the 0.50 to 1.27 mm (0.020 to 0.050 inch) range.

17. All drive pinion gears are manufactured to a nominal depth. There are no markings on the pinion for depth. Dial indicator reading is the shim selection.
18. Remove bearing caps and depth gauging tools.
19. Install the correct pinion shim to the pinion.

Differential Case Assembly

Install Or Connect





Tools Required:
J 25299 Differential Side Bearing Installer
J 8092 Driver Handle
J 8107-2 Differential Side Bearing Remover Plug
1. Lubricate all parts with axle lubricant.
2. Thrust washers to the side gears.
3. Side gears to the differential case.
- Install the side gears on the same side as removed.
4. Pinion gears to the differential without the thrust washers, as follows:
a. Place one pinion gear on the side gear and rotate the gear until the pinion is exactly opposite from the differential opening.
b. Place the second pinion gear on the side gear so the pinion gear holes line up.
c. Rotate the pinion gears into place, and verify the pinion gears line up with the pinion shaft holes.
5. Pinion thrust washers.
- Rotate the pinion gears toward the differential opening enough to slide in the pinion thrust washers.
6. Pinion shaft.
7. Pinion shaft lock bolt.
- Use a new pinion shaft lock bolt.
- Check that the mating surfaces of the differential case and the ring gear are clean and burr free.





8. Ring gear to the differential case, as follows:
a. Install two threaded studs into the ring gear on opposite sides.
b. Place the ring gear on the case and align the studs with the holes in the case.
9. Ring gear bolts.
- Tighten the ring gear bolts alternately and in stages, gradually pulling the ring gear onto the differential case.
- Tighten:
The ring gear bolts in sequence to 120 Nm (90 ft. lbs.).





10. Differential side bearings using J 25299, J 8092, and J 8107-2 or equivalents.
- Place J 8107-2 or equivalent in the differential case on the side opposite of bearing installation to protect the differential case.
- Drive the bearing onto the case using J 25299 and J 8092 or equivalents.
11. Differential case to the axle housing.

Side Bearing Preload Adjustment

Tool Required:
J 22779 Side Bearing Backlash Gauge





- The differential side bearing preload adjustment must be made before installing the pinion.
- The differential case side bearing preload is adjusted by changing the thickness of the left and right shims equally. This procedure will maintain the original backlash.
- Production shims are cast iron and are not to be reused. Measure the production shims and spacers one at a time and add the measurements together to obtain the sizes of the left and right shim packs.
- Service spacer thickness is nominal at 4.32 mm (0.170 inch).
- Service shims are available from 1.02 mm to 2.54 mm (0.040 to 0.100 inch) in increments of 0.101 mm (0.004 inch).
- Make sure the side bearing surfaces are clean and free of burrs.
1. Place the case with the bearing cups installed into the axle housing, as follows:
a. Lubricate the axle bearings with axle lubricant.
b. Support the case to keep it from falling into the axle housing.





2. Insert J 22779 or equivalent between the axle housing and the left bearing cup.





3. Move the tool back and forth in the bore while turning the adjusting nut to the right until a noticeable drag is produced, as follows:
a. Tighten the lock bolt on the side of the tool.
b. Leave the tool in place.
4. Install a service spacer and service shim between the right bearing cup and axle housing.
5. Determine bearing preload by inserting progressively larger feeler gauge sizes between the axle housing and service shim, as follows:
a. Push the feeler gauge downward so it contacts the shim at the top and bottom, and then contacts the axle housing.
b. The point just before additional drag begins is the correct feeler gauge thickness. This is the zero setting without preload.
6. Remove the strap, J 22779 or equivalent, service spacer, service shim, feeler gauge, and differential case from the axle housing.








7. Measure J 22779 or equivalent, in three places using a micrometer. Average the readings.
8. Add the dimensions of the right side service spacer, service shim, and feeler gauge.
9. For an initial backlash setting, move the ring gear away from the pinion by subtracting 0.25 mm (0.010 inch) from the ring gear side shim pack and adding 0.25 mm (0.010 inch) to the shim pack on the opposite side.
10. To obtain the proper preload on the side bearings add 0.10 mm (0.004 inch) to the measurement of each shim pack.
11. Install the differential.

NOTICE: Proper pinion depth setting is a two-step procedure.
a. Setup dimension arrived at with the indicator to be considered a starting point.
b. Gear tooth pattern check is necessary to "fine tune" the pinion depth and may indicate additional shim changes to the pinion stem. Both procedures must be performed to ensure proper axle performance and prevent system damage.

Pinion Installation





Install Or Connect
Tools Required:
J 5590 Rear Pinion Bearing Cone Installer
J 23911 Pinion Oil Seal Installer
J 8614-01 Pinion Flange Holder





1. The pinion inner bearing using J 5590 or equivalent.
- Drive the bearing on until the cone seats on the pinion shims.
2. A new collapsible spacer.
- Lubricate the pinion bearings with axle lubricant.
3. Pinion to the axle housing.
4. Outer pinion bearing onto the pinion using J 5590 or equivalent.
- Hold the pinion forward from inside the case while driving the bearing onto the pinion.
5. Pinion oil seal using J 23911 or equivalent.
6. The pinion flange by tapping it with a soft-faced hammer until a few threads show through the pinion flange.
7. The pinion washer and nut while holding the pinion flange with J 8614-01 or equivalent.
- Tighten:
a. The nut until the pinion end play is just taken up. Rotate the pinion while tightening the nut to seat the bearings. Once there is no end play in the pinion, the preload torque should be checked.





b. Remove J 8614-01 or equivalent. Using an inch-pound torque wrench, check the pinion preload by rotating the pinion with the wrench. Preload should be at or below 2.7 to 3.6 Nm (24 to 32 inch lbs.) on new bearings, or 1.0 to 1.4 Nm (8 to 12 inch lbs.) for used bearings.
c. If the preload torque is below the specified values, continue torquing the nut in small increments. Check the preload after each tightening. Each tightening increases the bearing preload by several pounds. If the bearing preload is exceeded, the pinion will have to be removed, and a new collapsible spacer installed.
d. Once the specified preload has been obtained, rotate the pinion several times to ensure the bearings have seated. Recheck the preload and adjust if necessary.
8. Differential case.

Backlash Adjustment
1. Install the differential case, bearing cups, spacers, and shims.
2. Rotate the case several times to seat the bearings.
3. Install a dial indicator to the case using a magnetic base.





4. Place the indicator stem at the heel end of a tooth.
- Set the dial indicator so the stem is in line with the gear rotation and perpendicular to the tooth angle.
5. Install the differential bearing caps and bolts.
- Tighten:
Bolts to 75 Nm (55 ft. lbs.).
6. Check and record the backlash at three or four points around the ring gear.
- The pinion must be held stationary when checking backlash.
- The backlash should be the same at each point within 0.05 mm (0.002 inch). If the backlash varies more than 0.05 mm (0.002 inch), check for burrs, a distorted case flange, or uneven bolting conditions.
7. Backlash at the minimum lash point measured should be 0.13 to 0.23 mm (0.005 to 0.009 inch) for all new gear sets.
8. If the backlash is not within specifications, move the ring gear in or out from the pinion by increasing the thickness of one shim, and decreasing the thickness of the other shim the same amount. This will maintain the correct axle side bearing preload.
- Moving 0.05 mm (0.002 inch) worth of shim from one side of the differential to the other will change the backlash adjustment by 0.03 mm (0.001 inch).
9. When the backlash is correctly adjusted, remove the bearing caps and shim packs.





10. Select a shim 0.10 mm (0.004 inch) thicker than the one removed from the left side. Insert this shim between the spacer and left bearing race.
11. Install the left bearing cap and bolts.
- Do not tighten.
12. Select a shim 0.10 mm (0.004 inch) thicker than the one removed from the right side. Insert the shim between the spacer and right bearing race, and drive the shim into place.
13. Install the right side bearing cap, and bolts.
- Tighten:
Bolts to 75 Nm (55 ft. lbs.).
14. Recheck the backlash and correct as necessary.